I was asking about both. I'm bassically building my fixie from random bike parts in this stranger I mets basement. He has so many bike parts and bikes and stuff. He's giving mr this cheap crankset for now that has like 44 teeth and I'm not sure of the arm length. But he is offering to sell me shimano 600 crankset for about $20 or less. It comes with like a 52 tooth chain ring and a 39 tooth chain ring and the crank arms length is 170. Would it be could to buy it? Or buy a new one from a store?